Hi,
So i was planning to put an amplifier and 2 subs in the trunk of my 05 w211 sedan .
The amplifier needs a + and - which i can easily get from the battery in the trunk.
The Amplifier also needs a low input + remote wire

My plan was to get a high level -> low level converter
And a High level -> remote converter

So my question is where would be the easiest place to pick up the High level input signal ?

I have Audio 20 system if that is for any help,

is there any cables around the rear deck / parcel shelf ?

made a quick overview schematic



Thanks in advance